Can farming systems foster soil carbon sequestration ? a systemic and multiscale approach

International audienceQuestioned on the 4/1000 initiative on soil carbon (C) sequestration to face climate change (CC), DSCATT project explores the potential for sequestering C in cultivated soils, taking into account the sustainability of agricultural practices in the context of global changes. We propose to link the academic and local knowledge on processes governing the soil carbon sequestration, to co-design with farmers and communities appropriated strategies. At field level, researches focus on the relation between biomass productivity and soil C sequestration under different practices. The regulation of the forms and the residence time of C in soils are studied, as also the interactions between nutrients cycling and C storage including the processes occurring in deeper horizons of soils. At the farm scale, DSCATT will focus on cropping and farming systems impacts regarding household livelihoods and food security highlighting social and economic constraints to adopt soil use management innovations. At the territory (or farmers' network) level, the organic matter flows and its control by local institutions or public policy will be studied. The project will assess the impacts of possible social arrangements on soil C sequestration dynamics, economic performance, food security and other co-benefits at the scale of territory. This knowledge and the viewpoints of the farmers involved are shared and used for a transdisciplinary assessment and co-designing several C sequestration strategies in agricultural soils. Considering changes and uncertainties, a multi-criteria and prospective evaluation approach is proposed. It will allow iterations between evaluation and redefinition of strategies to cope with global changes in agriculture. This original approach including a multidisciplinary research and local knowledge at multiple levels of space and time is implemented on different cases studies in Sub Saharan Africa and in Europe